Improvement in files



UNITED STATES PATENT OFFICE.

MILTONYD. VHIPPLE, OE CAMBRIDGE, ASSIGNOR TO THE 'IIIPPLE FILEMANUFACTIIRING COMPANY, OF BALLARD VALE, MASSACHUSETTS.

IMPROVEMENT IN FILES.

Specification forming part of Letters Patent No. 34,866, dated Aprill,1862.

To @ZZ whom, t may concern.-

Ie it known that I, MILTON D. WHIPPL-E, of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented. an Im'- provedFile, of which the following is a full, clear, and exact description,reference being had to the accompanying drawings', making part of thisspecification, in which- Figure l is a view of a round or rat-tail fileof my improved manufacture; Figf, a,

view of portion of the same enlarged; Fig. 3, a View of a half-roundfile, the curved sur- -face of which is cut in the same manner as therou/nd tile. l

Round files and those which Iare' partly round or have one of theirfaces curved around the axis of the file are usually made with the frowsof teeth extending in straight lines froui one end of the file to theother. EachV tooth in these lines being formed by a .cut in the metal ofthe file-blank which is on` such curved surface from one 'endetfthe`tile' toward thev other. That others skilled in the art may-'understand`'and 'use -my invention, Iwill proceed to describe the manner in whichl have carried it" out.

In the said drawings the t-eetha` 7J c d, dsc., Figs. 1 and 2,1 windspirally around the le from one end to the other of it. 'lo producethis, the blank` is revolved by suitable machinery around its axis whilethe cutting of the teeth progresses from one'end of the file toward theother. The machine which I have found most convenient fortsis purpose isthat for which Letters Patent of the United States Were granted me the7th day of October, A.

D. 1856, suitable gears being attached to the spindle which carries theblank to give it the required rotation.

The file` shown in Fig. 3 may have its rounded surface vcut in the sainemachine, three tiles being secured to the faces of a triangular mandrel,Vwhich is then revolved slowly as the cutting-proceeds. 'tha tile so et(either round or part round) a round hole may be tiled or a' curvedsurface be made smooth, as the rowsof teeth do not lie in lines parallelwith the direction of cut of the file and do lnot tend. to score thesurface being filed into grooves.

What I claim as my iiryention, and desireto secure by Letters Iatent4 asanew article of manufacture, is-

A round or curved surface'ie the teeth of which arecut in rows windingspirally, suhf stantially as specified.

MILTON D. WHIPPLE Witnesses: i

THOS. R. ROACH, f EDMUND MASSON.`

